High throughput catalyst testing has been often accomplished via the “massively parallel” approach discussed in High-Throughput Screening in Chemical Catalysis (2004 Wiley-VCH Verlag GmbH & Co. and KGaA, Weinheim. In this prior art, an array of materials are tested as a single batch in a manner that is highly dependent on manual operation. In this experimentation approach, each well in the array is loaded with a catalyst, sealed and then heated to a single operating temperature. Once at temperature, a reaction (typically, hydrocarbon (HC)) testing proceeds. Any characterization after reaction (i.e. BET analysis, coke content) requires a separate operation. Each catalyst from the array requires the one-by-one manual discharging, segregating, weighing and re-loading into each addition characterization device. As a whole, the sequential characterization of catalysts becomes the slow step and is no longer high-throughput. Although the testing and characterization results and operation under this prior art approach are naturally disparate, the inclusion of both is necessary to generate a complete evaluation of a catalyst.
Parallel testing of catalyst reactors has been used for materials that require long times to test. However, parallel testing such as that referenced in German Patent No. DE19809477C2 is not always effective in evaluating materials in which reaction testing and characterization techniques must be combined to present a complete analysis. For example, a significant amount of carbon is deposited on materials that are evaluated in heterogeneous reactors at high temperature. Without a sequential catalyst characterization, the amount of coke deposited on the catalyst must be calculated via carbon balance. However, this methodology is unreliable because it requires that all species be measured and be measured accurately. Missing components and propagation of error lead to highly inaccurate, scattered results. Thus, calculating coke from all of those measurements is rendered unusable.
The direct measurement of coke (likely via combustion) is not a viable solution for parallel reactor systems because the arrays of materials may have to be unloaded from the reactor into a new reactor for de-coking and tested one-by-one. Alternatively, the reactor in the parallel method may have to be transferred to another experimental set-up. Another approach is to redesign the hydrocarbon feed system to include both air and hydrocarbon feeds that are appropriately separated by interlocks (although possible, also of considerable hazard) to accomplish the coke measurement. All of these approaches become a bottleneck to high-throughput experimentation.
Parallel apparatus by nature are complex mechanisms. Compromise must be reached between data quality and complexity. As a result, parallel apparatus do not contain sufficient instrumentation to control key process parameters i.e. pressure, flow, and temperature for each individual reactor. In addition, some parameters have a limited range of operation temperature for “massively parallel.” While catalyst performance can be tested for many catalysts at once, data quality suffers. This leads to high variability in measured results.
A need exists for an improved method of testing catalysts and catalyst systems to alleviate the aforementioned issues associated with the prior art technique of using the massively parallel technique.